Apparatus for molding glass



June 7, 1949. n H. P. HOOD 2,472,660

APPARATUS FOR MOLDING GLASS Filed Feb. 25, 1944 Patented June 7, 1949 gaat APPARATUS FOR MOLDING GLASS Harrison P. Hood, Corning, N. Y., assignor to Corning Glass Works, Corning, N. Y., a corporation of New York Application February 25, 1944, Serial No. 523,874

3 Claims.

This invent-*on relates to the molding or shaping of plastic glass with a mold and has for its primary object the shaping of a plastic mass of glass by means of a mold but without the use of a plunger.

Another object is to provide an apparatus for shaping glass in a mold without a plunger.

Another object is to provide an apparatus for hligh speed production of very small articles of g ass.

Another object is to provide an apparatus for high speed production of glass jewels for the bea-rings of delicate instruments.

The above and other objects may be accomplished by practicing the invention to be more fully described in the following specification, claimed in the appended claims and illustrated in the accompanying drawings in which:

Fig. 1 is an elevation partly in section of a glass shaping apparatus adapted for the production of small glass articles such as bearing jewels in accordance with my invention;

Fig. 2 is an exaggerated cross sectional View of a glass bearing jewel made in accordance with my invention. l

In Fig. 1 a closed chamber, generally designated I0, has sidewalls which in the present instance are composed of a glass tube Ii, but which may be composed of other materials such as metal. The tube II is provided with end closure members I 2 and i3 secured by bolts if! and sealed to the tube I I with gaskets I5.

The closure member i2 is provided with a gob delivery tube I6, having a receiving end iii and a delivery end lll, which is composed of metal and which passes through the member i2 and is rmly attached thereto. The delivery end @I of the tube I@ is within the chamber lil and the receiving end lill is outside the chamber and adjacent a gob feeding means which in the present instance comprises a glass rod Il fed by rollers I3 through the name of burners I9. Member i2 is also provided with a suction tube 2@ through which a subatmospheric pressure may be produced within the chamber Ill by suit-able evacuation means, such as a vacuum pump (not shown).

Within the chamber I tube l5 passes through leg 42 of a U-shaped mold support 2I which is held rigid on tube I6 by a set screw 25. Arranged below tube IG a mold assembly, generally designated 22, passes through leg 43 of support 2| and is adjustably held thereto by a set screw 25. Mold 22 has a movable bottom 23 adapted to be raised by a pin 24.

The closure member I3 is provided with a vent 2 2E which communicates with the chamber it) through an air lock comprising an intermediate chamber 2l. The air lock is provided with. a poppet valve 28 and a piston valve 29. The valves are mounted on a rod Si) which extends through the piston 29 and is provided with an end knob 3| and a cross bar 32. The latter is also slidably attached to a pin 33 which is rigidly mounted in the outer face of the closure member I3 and which is provided with a compression spring 34'. The spring 34 acts through the cross bar 32 and rod 3!) to hold the valve 2&3 in a nor-- mally closed position, the valve 29 being at the same time so adjusted as to leave the vent 2G open. Pressure on the knob 3l will compress the spring 34 at the same time moving the valve 23 to close the vent 2S and lifting the valve 23 to place the chambers It and 2l in open communir cation.

The valve 28 is provided with a side arm 35 extending laterally beneath the pin 26. and a rod 36 extending vertically through a hole provided therefor in leg i3 of the support 2I. The rod 33 terminates with a laterally extended strip 3i of spring steel or other highly elastic metal the end of which bears against the lip of the mold 22.

In operation, thev subatmospheric pressure in-4 duced within the chamber Iii by the suction tube 2i? creates a -continuous high speed iniiow of air through the tube I6. A gob of molten glass severed from the glass rod II by the flame of the' burners i9 is drawn into the receiving end It@ of the tube I6 and is propelled through the tube by the flow of air to strike within the mold 22 withl a force sucient to cause the gob immediatelyl to assume the shape of the mold. Coincidentally with its shaping the gob is cooled by Contact with the mold and the inowing air from the tube I6. instance is a bearing jewel and has the form which is illustrated in exaggerated cross section in Fig. 2.

The mold is evacuated by applying pressure to, the knob 3l, whereupon the side arm 35 moves to,

engage the pin 24 and thereby lift the bottom 23 with the shaped glass article upon it. At the same time the elastic strip 3l actuated by the rod 36 moves up and across the face of the mold 22 displacing the shaped glass article from the elevated mold bottom 23. The displaced glass article falls to the bottom of the chamber I il and passes into the airlock 2l through the opening left by the valve 28 which was lifted from its seat when the knobi3| was pressed, as mentioned above. When pressure is removed from the knob,

The molded glass article in the present the spring 34 acts to return the valves and other moving parts to their normal position. The vent 26 which had theretofore been closed by the valve 29 is thereupon opened and the glass article is free to pass through the vent 26 to the outer air.

It is to be understod that the molding of glass articles off such, small magnitude as` jewel. bearings and the like must be accomplished at, a very:

high rate of speed. The tiny gob cools so rapidly that very little time is available for transferring the gob to the mold and subsequently shaping it.

It is an outstanding feature of my-inventi'on that by means of the apparatus hereinbefore described the gob can be conveyed to. the. mold, inan in.- credibly short space of time and no additional time is required for shaping the gob in the mold. Speed sufficient for my purpose is to be obtained only by a pneumatic means for delivering. the gob to the mold.

Inthe manipulation of applicants apparatus the velocity of the inflowing air and hence of the.

gob through the tube t6 maybe regulated by and is proportional to the degree of reduction of. pressure in the chamber l0 or the suction applied to the suction tube 20. I have found that too high a` velocity results in tooY violent an impact of the glasswith themold and causes the molten glass to splash. and formmisshapen articles. As the size of but may be used for the production. of different..

and! or larger articles within thescope of the fol.- lowing. claims.`

Ihe term gob isused. herein with the meaning4 which` it normally, has in the glassv workingr art and in the following claims a gob of glass means a. discrete. and unsupported, mass of glass. having substantiallyuniform viscosityV through-.

out.

I claim.:

1.A In a. glassshaping apparatus. a closed. chamber. a vertically. disposed gob delivery tube hav-4 ing. its delivery end. terminating inside said chamber, anv open topmold within said chamber arrangedbelow andspacedfrom the delivery end of said tube, and a suction line` in communication with said'. chamber for creating. a subatmospheric pressure. therein to accelerate the delivery of a gob tosaid mold..

2. In a glass shaping apparatus, a closed charnber, a vertically disposed` gob delivery tube having itsdelivery end terminating within said chamber.. a. mold having anopen top and having a bot,-

tom movable vertically to the top thereof arranged within said chamber below and spaced from the delivery end of said tube a distance at least equalling the height of the mold cavity, a suction line in communication with said chamber for creating a subatmospheric pressure therein so as. to create a.hgh velocity airv flow through said tubetowarrdlsaid mold and thus accelerate the delivery of a gob thereto, mechanism for elevating said mold bottom to raise a formed article clear of said mold, means for removing an article from the raisedmoldbottom, and means including said mechanism. for providing a passage for the gravitati'onal' removal.' of an article from said chamber whle-thesubatmospheric pressure is being maintained therein.

3'. In a glass shaping apparatus an open top moldhaving a vertically movable bottom, a closed chamber containing the mold, a gob-delivery tube extending through a wall ofthe chamber and arranged in a position to deliver a gob to the mold,l

means for creating'V a subatmospheric pressure within the chamber whereby themovement of the gob through the tube and into the mold is accelerated as required. to shape the. gob into an article ofthe interior contour of the mold upon its deposit therein, means for raising said` mold bottom to elevate the shaped article above the.

mold and for laterally discharging the article from the raised mold bottom, a relatively small chamber arranged below said closed chamber having a normally. open passage to atmosphere and a normally closed passage to said closed chamber respectively affording apath forv passing an article discharged from said mold bottom to atmosphere, said mold bottom raising means including means for closing, the first passage and for opening the second passagev while an article is being dischargedY from said mold bottom, to clear the path for an article, to said small chamber and for thereafterv reclosing the second passage and opening the firstA passage, to clear the path for the article to atmosphere. while maintaining the subatmospheric pressure within. said closed chamber.

HARRISON. P: HOOD.

REFERENCES CITED The following references are of record in the le of thisA patent:

UNITED STATES PATENTS Niunber Name Date Re. 15,600 Lorenz May 15, 1923 1,742,098. Rankin Dec. 31, 1929 1,809,793v Stenhouse et al. June 9, 1931 1,831,548 Slick Nov. 10, 1931 1,845,491 Eckert Feb. 16, 1932 1,904,977 Collins Apr.v 18, 1933 2,038,519. BarnardA Apr. 28, 1936 2,076,502 Moscini Apr; 6, 1937 2,130,702 Wadsworth Sept. 20, 1938 2,274,105 Stewart et al, Feb. 24, 1942 2,333,076. Stewart Oct. 26, 1943 

